Ok first of all this is one of the coolest prank you can play on your friends if they do not know anything about Windows Operating System !

Walk up to any of your friend and ask them to create a folder named CON or in fact you cannot create a folder named any of these keywords : CON, PRN, AUX, NUL, COM1, COM2, COM3, COM4, COM5, COM6, COM7, COM8, COM9, LPT1, LPT2, LPT3, LPT4, LPT5, LPT6, LPT7, LPT8, and LPT9.

They simply won’t be able to, because Windows will not let you create a folder of any of the keywords mentioned above for a simple reason that these keywords are used by Windows internally and are reserved Keywords. CON was used for CONSOLE, PRN for PRINTER, AUX for AUXILIARY DEVICE, LPT’s for PARALLEL PORTS and such. Microsoft has taken this initiative to avoid any conflict that may arise as a result of using these keywords.

Now if you are wondering whether if you can create a folder named CON, AUX or any other reserved keyword, the answer is YES. There is an evil way to achieve this, but its definitely not advised, as this can create ambiguity. Try this at your own risk.

Here’s how you can achieve this.

1> Open the command prompt on your system by clicking on Start –> Run and then type cmd

Get the full path to your desktop and put it in between the double quotes where you have <full-path-to-your-desktop>.

3> Hit Enter.

That’s it, now you’ll have a folder named CON on your desktop, now follow the same for all the other keywords !

You are done with creating the folder, now what ? Well you need to delete the folder you created. But try deleting it, you won’t be able to!! Surprised ? Well you had to be, but don’t worry, there is an easy way to delete this folder. To remove the folder you created, follow the steps:

1> Open the command prompt on your system by clicking on Start –> Run and then type cmd